PTL 1 discloses a structure of a metal band, an end portion of which is coupled with a pair of end plates arranged at both end surfaces of layered square batteries, and which fixes the square batteries in the layered state in a compressed state.
Further, PTL 2 discloses a structure of a battery pack structure, which includes a layered body in which a plurality of layered batteries is sandwiched by a first sandwiching member and a second sandwiching member, and a fastening member formed to accord with the dimension of the layered body, and an objective is to achieve a structure in which dimension change is less easily caused due to deformation of the fastening member.